163721549 has 2 divisors, whose sum is σ = 163721550. Its totient is φ = 163721548.

The previous prime is 163721533. The next prime is 163721561. The reversal of 163721549 is 945127361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161747524 + 1974025 = 12718^2 + 1405^2 .

It is an emirp because it is prime and its reverse (945127361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 163721549 - 2⁴ = 163721533 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163721149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81860774 + 81860775.

It is an arithmetic number, because the mean of its divisors is an integer number (81860775).

Almost surely, 2^163721549 is an apocalyptic number.

It is an amenable number.

163721549 is a deficient number, since it is larger than the sum of its proper divisors (1).

163721549 is an equidigital number, since it uses as much as digits as its factorization.

163721549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 38.

The square root of 163721549 is about 12795.3721712188. The cubic root of 163721549 is about 547.0604037227.

The spelling of 163721549 in words is "one hundred sixty-three million, seven hundred twenty-one thousand, five hundred forty-nine".